One of the largest lenses of its kind ever created, this former ship beacon has been brought down to Earth.

The last Victorian market in Belfast.

It was once nicknamed "the most bombed hotel in Europe."

A giant sculpture of the legendary "Salmon of Knowledge" celebrates the return of fish to Belfast's River Lagan.

A palatial former bank building now houses what may be the poshest art venue (and former Tesco) in Belfast.

A clock designed to run with perfect accuracy for 10,000 years.

Abstract dinosaur models in London.

Hidden behind a wall for decades, this masonic lodge was only rediscovered during renovations.

This hidden green space is the city's second largest conservatory.

A collection of comics, graphic novels, animation and caricatures devoted to exploring this often overlooked art form.

London's old-school healing garden.

Repository for more than 22 million pickled specimens.

The television series' iconic giant foot was borrowed from this classical painting.

The largest of London's subterranean rivers and once a mad, bad center of London life.

This 1920s Dutch barge is now a floating bookstore.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

A mysterious artist-run cabinet of curiosities and library.

London's smallest police station is barely the size of a phone booth.

The remains of Crystal Palace Great Exhibition of 1851.

The final resting place to 300 Victorian-era pets hides inside the city park.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

Hear the quietest sound from across the dome.

A makeshift shrine to the late rock star is still kept up on the nondescript façade outside 1 Logan Place.